Door or window alarm.



'No. 708,327. Patented Sept. 2,1902.

ms. E BEBSTEIN. 000R 08 WINDOW ALARM.

(Application filed June 3, 1901.)

2 Sheets-Sheet I.

No. 708,327. Patented Sept. 2, I902.

J. G. EB'ERSTEIN.

DOOR 0B WINDOW ALARM.

7 (Application filed June 3, 1901.) (No Model.) 2 Sheets-Sheet -2.

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llnrr nn rains ATENT FFlGEt JOHN G. EBERSTEIN, OF CHICAGO, ILLINOIS,ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO JOHN J. HOVEY, JOHN F.DEAN, AND R. ADAM BRACHVOGEL, OF CHICAGO, ILLINOIS.

DOOR OR WINDOW ALARM.

SPECIFICATION forming part of Letters Patent No. 708,327, datedSeptember 2, 1902.

Application filed June 3,1901. Serial No. 62,977. (No model.)

To all whom, it may concern:

Be it known that 1, JOHN G. EBERSTEIN, a citizen of the United States,residing in the city of Chicago, county of Cook, and State of Illinois,have invented a new and useful Improvement in Door or Window Alarms, ofwhich the following is a specification.

My invention relates to door and window alarms automatically set off bythe opening of the door or window whereto the alarm is adjusted; and theobjects of my invention are, first, to provide an alarm which shallrequire no fixtures, but which may be easily adjusted and removed, and,second, to provide an alarm of simple construction and positive action.I attain these objects by the mechanism illustrated in the accompanyingdrawings, in whicht Figure l is a face or front view of the com pletedevice. Fig. 2 is aperspective View illustrating the manner of adjustingthe alarm to a window. Fig. 3 is a face view of the device, showing thebell removed for the purpose of exposing the interior mechanism. Fig. 4is a face view of the chief members of the releasing mechanism. Fig. 5is a rear view, with the casing removed, showing the mainspring; andFig. 6 is a transverse sec:

tional view taken on the line 66, Fig. 3, looking in the direction ofthe arrows.

Similar characters refer to similar parts 7 throughout the severalviews.

a represents the central plate, whereto the framework of the device isattached and stitutes a part of the gear-frame, being rigidly secnred tothe central plate 0.. Between lets m m upon the escapement-lever- 11.

By means of the said plate h and the main or first gear-wheel g is aratchet 2', rigidly attached to the arbor Z) and detained by the pawlj,pivoted to the frame-plate h. When the bell d has been screwed tightupon the threaded extremity of the arbor b, if the frame-plates a and 7bare held stationary the further rotation of said bell causes the saidarbor b to be rotated in the frame of the device, and said arbor isprevented from rotating backward on account of the operation of saidratchet and pawl. Now the main gear-wheel g, sleevef, and oasing 6rotate as a single piece, and as the gearwheel g is prevented fromescaping by certain devices attached to the main frame and hereinafterdescribed it follows that the rotating of the arbor b winds up themainspring c in the casing e. In other words, when the main gear 9 isheld fixed in the main frame and since the casing c and gear 9 arerigidly connected and also since the mainspring is con nected at one endto the said arbor and at the other to said casing c it follows that therotation of the arbor b will wind up the mainspring, so that the casingwill tend to rotate so as to unwind said spring when the gear 9 ispermitted to rotate in the main frame. The escapement mechanism wherebysaid gear g is controllably permitted to rotate in the main frame willnow be described.

The escapement-wheelkis revoluhlymounted upon a suitable arbor in themain frame and is normally detained by means of the pal- Said wheel k isconnected by a train of gearing 0 0 with the wheel g,and the mainspringctherefor tends to drive said escapement-wheel 7c.

The hammer p is connected to the lever 91 by the arm q, and the partsare so related that when the pivoted lever 77. is not detained the forceof the escapemeut-wheel 7c acting upon the pallets m 172 will drive saidlever,so as to rock upon the pivot thereof and permit the intermittentrevolution or escapement of said wheel 70. The rocking or vibration ofsaid lever 11 causes the hammer to make a series of strokes upon thebell 61, thereby sounding an alarm.

The device for preventing the vibration of the lever 02 consists of aslotted detent r, havin g a tongue 5-, adapted to engage said lever. Apin 25 penetrates through said detent 1" into the plate a and forms aguide for permitting a limited travel of said detent. By means of thespring u, acting upon the detent 1, said detent is normally held so asto engage and prevent the vibration of the lever it. Near one extremitysaid detent has an arm 1;, extending transversely thereto and passingthrough a suitable aperture provided in the plate a. Said arm isscrew-threaded to engage an extremity of the controlling-rod to. Whensaid controlling-rod forces the detent r away from the lever 71, saidlever is released and permits the escapement of the wheel 7c.

Inclosing the spring 0, casing e, and adjacent parts is the lower casing00, which is dish-shaped and attached at its periphery to the centralplate (t by means of the tongues y g on said casing which enter thenotches a z on said plate. The controlling-rod to projects aconsiderable distance beyond the casing 00 and is preferably pointed atits outer extremity, as shown, for better sinking into the wood of thedoor or window whereto the device is to be adjusted. An arm 1 isattached to the lower casing 00 and has a turnedup portion 2, aperturedin such a manner as to form a guide for said rod to. Said arm 1 is alsoprovided with the sharpened prongs 3 3 on the opposite side of the lowercasing for sinking into and engaging parts of the floor or window. Asthe prongs 3 are secured to the main frame of the device and the rod '10is secured to the detent 4, which is movable therein, it follows thatthe movement of said rod relatively to said arm 1 operates said detentr, and thereby controls the operation of the device.

My invention is applied and used in the following manner: When it isdesired to call attention to the unauthorized opening of a window, theprongs 3 3 are placed upon the upper ledge of the lower sash and thepoint of the rod w is caused to engage the side of the upper sash, butin a loose manner, so that p the rod to is projected, and the detent 7'prevents the vibration of the hammer 19. When the device is adjusted inthis manner, as illustrated in Fig. 2, it is evident that either theattempted raising of the lower sash or lowering of the upper sash willcause the rod to to be forced into the framework of the device, therebycausing the sounding of an alarm in the manner above described.

It is within my conception that my device may be adjusted with certainadaptation to objects other than doors and windowsas, for example,drawers sliding within chests or casings.

WVhat I claim as new, and desire to secure by Letters Patent, is

1. In a burglar-alarm, a shell comprising two bowl-shaped parts havingtheir concavities adjacent and their peripheriesapproximatelycontiguons, the upper one of said parts constituting analarm-bell; a central plate socured to the lower of said shell part-sand extending across the device from the peripheries of said shellparts; an arm fixed to and extending in both directions from said lowershell part, one end of said arm having prongs for engaging an exteriorobject, and the other end of said arm having a turned-up portionperforated to form a guide; a main arbor mounted in and extendingthrough said central plate, and secured at one end to said bell; apulsative device inclosed between said central plate and said bell forsounding the latter; a spring-casing inclosed between said lower shellpart and said central plate, said spring-casing being connected to saidmain arbor for driving said pulsative device; a spring connected at oneend to said arbor and at the other end to said spring-casing; a plateslidingly mounted on said central plate and constituting a detent forcontrollably retaining said pulsative device; and a controllingrodsecured to said detent, said rod extending through the perforatedturned-up guide portion of said fixed arm, and said controlling-rodhaving means for engaging an exterior object.

2. In a burglar-alarm, the combination of a main framework, a mainspringcasing, a main arbor, a mainspring secured at one end to said casing andat the other end to said arbor, an alarm-bell attached to said arbor forwinding said spring, a ratchet-and-pawl device connecting said arbor andthe main framework for preventing the accidental improper release of themainspring, a pulsative esoapementdevice geared to said mainspringcasingfor sounding said bell; a detent operating upon said escapement, saiddetent having a slot for receiving a guide-pin and having a transversearm passing through an aperture in the central plate of the main frame,and said detent being slidably mounted upon said central plate andmaking contact therewith for the greater portion of the length of saidcentral plate thereby affording a firm bearing for said detent; acontrolling-rod secured to the transverse arm of said detent upon theside of said central plate opposite to the major portion of said detent;said rod having means for engaging an exterior object and prongs fiponsaid framework for engaging a second exterior object whereto the deviceis adjusted.

JOHN G. EBERSTEIN.

Witnesses:

R. A. BRAOHVOGEL, SADIE WOLF.

ITO

